


Supernova

by Carmenlire



Series: Tumblr Prompts [28]
Category: Shadowhunters (TV)
Genre: Alliance Rune (Shadowhunter Chronicles), But chill, Canon Compliant, Fluff and Smut, M/M, POV Magnus Bane, Possessive Magnus Bane, Post-Canon, Sex Magic, but like chill and alec is more than game
Language: English
Status: Completed
Published: 2019-08-11
Updated: 2019-08-11
Packaged: 2020-08-19 11:15:39
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,354
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20208835
Author URL: https://archiveofourown.org/users/Carmenlire/pseuds/Carmenlire
Summary: "Besides,” Magnus asks with a quick grin, “If I can’t share the alliance rune with my husband then who the hell can I use it with?”He watches the way Alec’s eyes darken and then he’s being pulled into a searing kiss that makes Magnus warm, no matter that it’s thirty degrees outside. When Alec finally steps back, his voice is hoarse as he says, “Home. Now.”





	Supernova

**Author's Note:**

> Prompt by intangibel: Malec playing with the Alliance Rune, +\\- magnus (being a little jealous?) not liking Lorenzo’s magic running through Alec, wanting it to be his. Alec loving Magnus’ magic. I hope you like this bel!

When Magnus notices, it’s a punch to the gut. It makes bile climb up his throat, seeing the nauseatingly yellow magic around Alec’s hands-- his Alec, his darling Alexander, using another warlock’s magic is intolerable.

And Lorenzo, the bastard, he _knew_. He knew how it would feel to see another’s magic around his fucking fiance.

Magnus is well aware that it’s neither the time nor the place for such a primal reaction. The truth is, the alliance rune had saved those closest to him and secured his own freedom from Edom.

That doesn’t mean that Magnus doesn’t almost choke on the knowledge, though.

Still, everything happens so fast after the rescue mission and it’s weeks later before it comes up again. The two of them are walking through Central Park and it’s the most peaceful Magnus can remember feeling in years-- decades maybe.

It’s winter and they’re bundled up in their coats and scarves and Alec’s wearing those fingerless gloves that Magnus adores even if he wonders how on earth Alec’s staving away frostbite. It’s quiet, snow spitting down, and it feels like they’re in their own little world.

Alec hauls him a little closer with his arm over his shoulder and Magnus hides a grin in his scarf, tightening his own arm that’s slung low around Alec’s back.

“You know,” Alec starts and when Magnus looks up, it’s clear that his husband is choosing his words carefully, that this is far from the spontaneous little conversation he’s clearing aiming for. “I love your magic.”

A little taken aback at the abrupt declaration, Magnus merely blinks. “Thank you, darling,” he says, nonplussed.

He looks up in time to see Alec roll his eyes, though he doesn’t know if it’s at himself or Magnus. Looking over, the breath stalls in his chest at the intensity in Alec’s gaze.

“What I mean is-- I love the feel of it, the way it seems to reach out to me sometimes, especially when you aren’t even paying attention. It feels familiar.” Magnus watches, entranced, as Alec swallows hard, as his tongue darts out to swipe across his lip. “It feels like home.”

Something melts in Magnus and he leans further into Alec. “Oh,” he says softly.

“Yeah.”

Alec looks like he wants to say something else but he doesn’t and Magnus doesn’t push. Instead, they continue strolling aimlessly down a path while Magnus’s head spins. It’s nothing new or unexpected but damn if Alec doesn’t know how to lay waste to Magnus’s defenses with the simplest of declarations.

His thoughts catch on Alec’s words, however, and his head snaps back up. “You said it felt familiar,” Magnus drawls. He raises a brow. “More familiar than a certain other warlock’s?”

Wincing, Alec doesn’t pretend not to know what Magnus is alluding to. “I’d much rather have been your partner for the alliance rune than Rey’s, I assure you. While it was cool, it felt like his magic was fighting me every step of the way.”

Filing away that useful bit of information, Magnus replies before his brain has a chance to catch up to his words. “Then let’s do it.”

He comes to a stop as Alec freezes and while he hadn’t meant to, he knows his voice had betrayed his irritation. He meets Alec’s eyes with a challenge in his own.

Breath catching as Alec steps close, as his husband cups his cheek and tilts his face up a bare inch, Magnus can’t look away as Alec asks, “You mean that,” in a low tone.

“I wouldn’t have said it if I didn’t mean it, Alexander. Besides,” he asks with a quick grin, “If I can’t share the alliance rune with my husband then who the hell can I use it with?”

He watches the way Alec’s eyes darken and then he’s being pulled into a searing kiss that makes Magnus hot, no matter that it’s thirty degrees outside. When Alec finally steps back, his voice is hoarse as he says, “Home. Now.”

Alec sits on the couch, twirling his stele absently in his hand. It's unfairly attractive and Magnus feels his stare land on him as he lights half a dozen candles around the living room. The late winter afternoon is gloomy, casting the loft in shadows. Taking their outerwear off, Magnus had rolled up his shirt sleeves as Alec had settled. Magnus feels a shiver wrack up his spine and can’t help but feel like the mouse to Alec’s cat.

A few minutes later, Magnus is done and he strolls over to Alec. Looking down at his husband, he blinks slowly and between one moment and the next, his glamour dissolves. He hears Alec’s breath catch and he grins as he steps so that Alec’s thighs are between his legs. 

Tilting Alec’s head up, he murmurs, “Are you sure about this, darling?”

Alec’s nodding before he’s even finished asking. “I can’t stop thinking about it,” he admits and a fire blooms in Magnus’s gut at the earnest words, at the way he reaches out and grips Magnus’s hips in steady hands. “I want all of you, Magnus.”

Magnus lowers himself until he’s straddling Alec and he holds out his arm. His voice is husky as he offers, “Mark me then, Alexander.”

Alec’s fingers dig into his hips for a moment and Magnus half hopes he follows through on his clear desire to push Magnus back onto the couch and do wickedly wonderful things to his body.

Instead, he takes a deep breath as if gathering his thoughts and wraps a hand around Magnus’s arm. His thumb brushes over the sensitive skin of his wrist and Magnus shudders in his hold. When he lifts his other hand and the tip of his stele touches him, though, Magnus can’t stop his instinctive flinch.

Memories course through him, flashes of a chair and restraints and an Alec he didn’t recognize. 

Catching the little movement, Alec stills, too. “You okay,” he asks softly. “I won’t hurt you-- besides the rune itself stinging a little as it’s applied-- but I don’t want to do anything you’re uncomfortable with.”

Shaking his head a little to clear it, it’s Magnus’s turn to take a steadying breath and when he looks up at Alec, his expression is serious but sure. “I want this. It’s just something new and unexpected and my body hasn’t quite caught up with my head.” He sees the hesitancy in the tension seeping into Alec and all he offers is a quiet, “Please.”

Alec nods to himself and then the stele is touching him once more. Alec draws the swirling lines in a competent hand and he wasn’t lying-- it does sting as the rune flares with light before settling into a deep crimson against his skin. The pain sears into him for one heartbeat, for two and three, before it settles back down and Magnus bites his lip at the feeling. 

It strikes him immediately that it’s different than the first and last time he was runed. This pain is comforting, familiar, something he wants to sink into. His mind’s a little hazy but he has a desperate wish to chase the sensation and when he shifts, biting back a moan, he knows that Alec’s picked up on his reaction from the way his gaze sharpens.

Magnus doesn’t say anything, though, and neither does Alec and as the heat banks back down, Magnus is struck by a different feeling.

There’s a connection there and it’s like he’s been jump-started. There’s a different energy buzzing under his skin and he has the sudden desire to-- to do something, anything, that can test the limits of the power he can feel simmering just below the surface, waiting to be tapped.

He doesn’t do any of that, though. Instead, he reaches for Alec’s stele and as soon as his fingers wrap around it, it glows red.

Alec doesn’t comment on the color and when Magnus darts a look up, it’s to see his husband’s unsurprised face.

“You knew?”

Raising a brow, Alec merely replies, “I know who I married.”

Huffing out a laugh, Magnus reaches for Alec’s wrist only to be stopped. He looks up, curious, but Alec just urges him to lean back. With enough room to maneuver, he pulls his shirt off, tossing it onto the floor next to him.

Tapping over his heart, Alec murmurs, “Right here.”

Swallowing hard, Magnus nods once. He’d studied the alliance rune that first day-- his eyes had burned into the rune Lorenzo had drawn on Alec’s arm and he’d poured his gaze over the scrap of paper Biscuit had drafted.

He draws the rune over Alec’s heart now with a steady hand. When he’s done, they both take a breath and Magnus rests his hand over Alec’s chest, feels his heart beating wildly underneath his palm.

Looking up, Magnus’s breath catches as his eyes lock on Alec’s. He reaches a hand up, running a thumb over his cheek.

Distantly, he thinks he understands Alec’s reaction to seeing his mark because seeing Alexander with gold eyes is one of the most stunning images Magnus has ever been treated to.

“Mine,” Magnus breathes, tipping Alec's head up, and he feels the shudder that rolls through his husband at the declaration, at the possessiveness lingering in his undertone. 

When his husband lifts a hand to put over his, they see the blue tendrils wrapped around his fingers at the same time and the breath is punched out of Magnus anew.

If seeing his mark on Alec was gorgeous, watching his magic wrap around his love is something else entirely. Magnus doesn’t have words for what the sight does to him, for the primal surge that rocks through him at seeing his magic-- his soul, his essence-- intertwined with Alec.

He’s not entirely aware of doing it but in a flash, he has Alec on his back, pushing him into the couch cushions, leaning over him with hands on his chest.

They both freeze for a moment as they realize what’s happened and then Magnus is grinning down at Alec and it’s sharp, wicked and teasing.

Before he can do anything else, though, Alec’s across the room. There’s a flush riding high across his cheeks and his eyes are glinting with challenge, with a look Magnus has only ever seen when the heat of a mission was thrumming through his blood.

“Catch me.”

Magnus has a second to register the words before Alec’s gone and it’s more instinct than anything else that has him giving chase.

It’s odd, to feel the power of runes running through him. They stay in the loft and Alec flashes from one room to the next, letting Magnus get close without quite managing to win. Magnus supposes it would be anticlimactic for vampires or even werewolves but warlocks have never had increased speed or strength. Magnus might be exceptionally fit for a human but any superhuman power comes from his magic and it’s a thrill to feel his heightened senses working in a totally different way than he’s used to.

There’s another piece of it, though, and he follows Alec, reaching through their connection. His magic binds them and he can feel it working in Alec. The ebb and flow, his power sparking in an unfamiliar body while still recognizing it on a molecular level.

It’s like Alec mentioned earlier, Magnus realizes. His magic has recognized Alec since the beginning, since before he used Alec’s strength to restore his depleted levels so long ago. It’s made a home in Alec for longer than Magnus realized-- it’s burrowed its way into his husband until Magnus is fairly stunned at how happy it feels to be in Alec, crashing through his system like a purring cat.

Clearing his head, Magnus redoubles his efforts and when he finally catches Alec, he pins him against the wall in the living room. He’s not quite aware of just how effective the strength rune is, however, and when Alec leans in and crashes their lips together, Magnus’s hands drag down his sides until they’re settling against his thighs and he’s pulling, both of them breaking apart to gasp in surprise as Magnus lifts Alec until he can wrap his legs around his waist.

Magnus doesn’t even break a sweat and he feels more than hears Alec groan, his own chest aching in response.

It quickly devolves from there but when Alec’s hands cup his face, the kiss turns impossibly deep and everything slows down until they’re grinding against each other and Magnus has the thought that they should probably move this to the couch or bed or, hell, the floor, but then Alec moves.

Magnus almost comes in his goddamn pants as his choked off cry echoes through the room. When he opens his eyes, it’s to see Alec staring at him, shock and delight flaring bright in his face as they have the same realization.

Alec’s hands had moved down until he was pressing desperate nails into the small of Magnus’s back. Without knowing how-- and the very small piece of Magnus’s brain that is still online is racing at the implications-- Alec had coalesced his own pleasure and doubled it back, pushing it into Magnus with a shock wave of feeling.

Sex magic is intimate and while Magnus loved it, particularly with Alec as the very willing recipient, it took extensive training and an emotional bond that had to be carefully cultivated.

The fact that Alec had had the alliance rune for less than an hour yet was able to do such a thing was nearly inconceivable.

Magnus gives very brief thought to pursuing it on an intellectual level but the desire still running through him quickly drowns that inclination out.

It looks like Alec is on the same page as they lean back into each other, mouths meeting in a kiss that’s as hot as it is desperate.

As Magnus steps away from the pillar, still holding Alec effortlessly, he turns toward the bedroom.

He can’t wait to _thoroughly_ test out the alliance rune’s abilities.

**Author's Note:**

> catch me on tumblr or twitter @carmenlire!


End file.
